What are they all about ???? And more to the point what on earth do you have to do to get a platinum one

I used to have one and I know about the Platinum trophies.

Platinum trophies can be earned by getting all the trophies and once you have them all, it will unlock the Platinum trophy.

As Batch said you get one for unlocking all the other trophies. I don't have a single one

The number of trophies you have all add up to give you your level - gold are worth more points than silver which are worth more than bronze

There's a guide here

http://www.ps3trophies.org/forum/games/18347-trophy-points-guide.html

Cheers mate ....although I can't see me getting many platinum ones , I have a mate who has 128470 gamerscore on xbox ..he's a bit anal about completeing games to the full ...and He dosent even have a platinum trophy !!

Im not bothered about trophies at all, its nice when one pops up but im not going for any at all.
Its nice not worrying about them for a while.
I like them on the xbox (the number helps) and im not hardcore about them, but i will go for them sometimes.

Hi Jellybean there is another link here, it converts the score of trophies to your xbox gamerscore

http://www.trophycalculator.com/

It shows how much your trophies calculate against your xbox gamerscore

Yeah mines fairly low compared to my Xbox gamerscore